code: def SFixed64ByteSize(field_number, sfixed64):
      return TagByteSize(field_number) + 8
  
imports: import struct
  from google.protobuf import descriptor
  from google.protobuf import message
label_desc: Use image node_id 15 for calling a global function with example usage: SFixed64ByteSize(field_number, sfixed64) and returns: unknown